Cam-and-groove couplers are used to connect and disconnect hoses or conduits. An example of a cam-and-groove coupler 100 is shown in FIGS. 1A-1D.
The cam-and-groove coupler 100 includes a male piece 102, which is insertable into a female piece 104 to releasably and sealingly connect the male piece and the female piece. Accordingly, if the male 102 and female 104 pieces are coupled to hoses or conduits, the hoses or conduits may be releasably and sealingly connected via the cam-and-groove coupler.
Each of the male 102 and female 104 pieces have a body portion 106, 108. Each of the body portions 106, 108 include a longitudinally extending bore 110, 112 defined therethrough. When the male 102 and female 104 pieces are secured together, the bores 110, 112 are in fluid communication with each other.
Each of the body portions 106, 108 further comprise a first end 114, 116 that is configured to receive a hose or conduit, such that the hose or conduit is in fluid communication with each of the bores 110, 112. For example, the ends 114, 116 can each be threadedly secured to a hose or conduit.
A second end 118 of the body portion 106 of the male piece 102 and a second end 120 of the body portion 108 of the female piece 104 are mateable together to releasably and sealingly secure the male 102 and female 104 pieces together. The second end 118 of the male piece 102 is insertable into the second end 120 of the female piece 104, and comprises a rounded groove 122 extending around the circumference of the body portion 106 of the male piece 102. The female piece 104 includes a first 124a and second 124b cam which are positioned on circumferentially opposed sides of the body portion 108 of the female piece 104. The cams 124a, 124b are connected to and actuated by first 126a and second 126b levers, respectively, which rotate about pivot pins 127a, 127b. 
The levers 126a, 126b each have an unsecured position, and a secured position. In the unsecured position, the levers 126a, 126b are positioned to extend generally transversely outwardly from the body portion 108 of the female piece 104, as shown in FIG. 1C. When the levers 126a, 126b are in the unsecured position, the cams 124a, 124b do not engage the groove 122, and the male piece 102 and the female piece 104 are not secured to each other. In the secured position, the levers 126a, 126b are positioned to extend generally along the body portion 108 of the female piece 104, for example generally parallel to the longitudinal bore 112. When the levers 126a, 126b are in the secured position, the cams 124a 124b are rotated to a position whereby they are inserted in the groove 122, as shown in FIG. 1D. Accordingly, the cams 124a, 124b engage the groove 122 to secure the male piece 102 and the female piece 104 together.
U.S. Pat. No. 3,439,942 to Moore discloses a retainer means for holding a lever arm of a cam-and-groove coupler. The retainer means includes a thin flat flexible resilient member including a planar first portion having an aperture therein receiving a pin that pivots the lever arm. The retaining means has a resilient second portion normally bent at an angle to the plane of the first portion and overlying and contacting the lever arm and holding it in place.
U.S. Pat. No. 6,206,431 discloses a safety assembly for a cam-and-groove coupler in which pull rings on the female unit serve to both release the coupling assembly and to maintain the coupling assembly locked against unintentional disconnection. In the locked conditions, the pull rings abut against ears on the housing of the female coupling unit to oppose unintended movement of the cam arms from the locked position of the cam arms to the released position of the cam arms. Upon intentional removal of the pull rings from abutment with the ears by an operator and pulling on the pull rings, the cam arms can be moved from the locked position of the cam arms to the released position of the cam arms to disconnect the coupling assembly.